Infrared touch panel

Claim 2

A touch panel comprising: a display surface having a defined perimeter; a multiplicity of light emitting elements and a multiplicity of light receiving elements; said elements located so that a multiplicity of light paths, defined by selected pairs of said light emitting and light receiving elements, cross said display surface and also intersect each other within the perimeter of said display surface; beam blockage detection means, coupled to said light receiving elements, for generating a path blockage signal when the amount of light received by a selected light receiving element corresponds to a blocked light path; and computer means, coupled to said light emitting and light receiving elements and said beam blockage detection means, for controlling the operation of said touch panel, including scanning means for sequentially enabling selected pairs of said light emitting and light receiving elements; and touch detection means, responsive to path blockage signals from said beam blockage detection means, for comparing said path blockage signals with predefined criteria which distinguish between a deliberate touching of said display surface and false or accidental touching of said display surface, and for generating an output signal indicative of the location of said object when said path blockage signals meet said predefined criteria.

Claim 3

A touch panel as set forth in claim 1, said touch detection means including means for comparing said path blockage signals from a plurality of scans of said display surface with predefined size and time duration criteria.

Claim 4

A touch panel as set forth in claim 1, said touch detection means including means for comparing said path blockage signals from a plurality of scans of said display surface with one or more criteria selected from the set consisting of: a minimum size criteria, a maximum criteria, and a minimum time duration criteria.

Claim 5

A touch panel as set forth in claim 1, including component failure detection means, including means for testing a selected light emitting element by performing the steps of enabling said selected light emitting element and a light receiving element across said display surface from said light emitting element, and testing for the presence of a blocking signal; enabling the same light receiving element and a second light emitting element which is located near said selected light emitting element, and testing for the presence of a blocking signal; and denoting the detection of a component failure if a blocking signal is detected when said selected light emitting element is enabled, but no blocking signal is detected when said second light emitting element is enabled.

Claim 6

A touch panel comprising: a display surface having a defined perimeter; a multiplicity of light emitting elements and a multiplicity of light receiving elements; said elements located so that a multiplicity of light paths, defined by selected pairs of said light emitting and light receiving elements, cross said display surface and also intersect each other within the perimeter of said display surface; beam blockage detection means, coupled to said light receiving elements, for generating a path blockage signal when the amount of light received by a selected light receiving element corresponds to a blocked light path; and computer means, coupled to said light emitting and light receiving elements and said beam blockage detection means, for controlling the operation of said touch panel, including scanning means for sequentially enabling selected pairs of said light emitting and light receiving elements; and touch detection means, responsive to path blockage signals from said beam blockage detection means, for comparing said path blockage signals with predefined criteria corresponding to a deliberate touching of said display surface by a human finger or similarly sized object, and for generating an output signal indicative of the location of said object when said path blockage signals meet said predefined criteria.

Claim 7

A touch panel comprising: a display surface having a defined perimeter; a multiplicity of light emitting elements and a multiplicity of light receiving elements; said elements located so that a multiplicity of light paths, defined by selected pairs of said light emitting and light receiving elements, cross said display surface and also intersect each other within the perimeter of said display surface; beam blockage detection means, coupled to said light receiving elements, for generating a path blockage signal when the amount of light received by a selected light receiving element corresponds to a blocked light path; and computer means, coupled to said light emitting and light receiving elements and said beam blockage detection means, for controlling the operation of said touch panel, including scanning means for sequentially enabling selected pairs of said light emitting and light receiving elements; and touch detection means, responsive to path blockage signals from said beam blockage detection means, for comparing said path blockage signals with predefined criteria corresponding to a deliberate touching of said display surface by a human finger or similarly sized object, and for generating an output signal indicative of the location of said object when said path blockage signals meet said predefined criteria.

Claim 8

A touch panel comprising: a display surface having a defined perimeter; a multiplicity of light emitting elements and a multiplicity of light receiving elements; said elements located so that a multiplicity of light paths, defined by selected pairs of said light emitting and light receiving elements, cross said display surface and also intersect each other within the perimeter of said display surface; beam blockage detection means, coupled to said light receiving elements, for generating a path blockage signal when the amount of light received by a selected light receiving element corresponds to a blocked light path; and computer means, coupled to said light emitting and light receiving elements and said beam blockage detection means, for controlling the operation of said touch panel, including scanning means for sequentially enabling selected pairs of said light emitting and light receiving elements so as to repetitively scan said display surface; failed component denoting means for denoting that specified ones of said pairs of said light emitting and light receiving elements are not functioning properly; and touch detection means, coupled to said failed component denoting means and responsive to path blockage signals from said beam blockage detection means, for determining whether an object is touching or adjacent to said display surface and for generating an output signal indicative of the location of an object touching or adjacent to said display surface when said path blockage signals correspond to intersecting block light paths; said touch detection means including means for ignoring, when determining whether an object is touching or adjacent to said display surface, path blockage signals corresponding to pairs of said light emitting and light receiving elements denoted by said failed component denoting means as not functioning properly.

Claim 9

A touch panel comprising: a display surface having a defined perimeter; a multiplicity of light emitting elements and a multiplicity of light receiving elements; said elements located so that a multiplicity of light paths, defined by selected pairs of said light emitting and light receiving elements, cross said display surface and also intersect each other within the perimeter of said display surface; beam blockage detection means, coupled to said light receiving elements, for generating a path blockage signal when the amount of light received by a selected light receiving element corresponds to a blocked light path; and computer means, coupled to said light emitting and light receiving elements and said beam blockage detection means, for controlling the operation of said touch panel, including scanning means for sequentially enabling selected pairs of said light emitting and light receiving elements so as to repetitively scan said display surface; failed component denoting means for denoting that specified ones of said pairs of said light emitting and light receiving elements are not functioning properly; and touch detection means, coupled to said failed component denoting means and responsive to path blockage signals from said beam blockage detection means, for determining whether an object is touching or adjacent to said display surface and for generating an output signal indicative of the location of an object touching or adjacent to said display surface when said path blockage signals correspond to intersecting block light paths; said touch detection means including means for ignoring, when determining whether an object is touching or adjacent to said display surface, path blockage signals corresponding to pairs of said light emitting and light receiving elements denoted by said failed component denoting means as not functioning properly.

Claim 10

A touch panel as set forth in claim 6, including component failure detection means for detecting, during a plurality of consecutive scans of said display surface by said scanning means, the generation of a path block signal by said beam blockage detection means for at least a first one of said light paths and the absence of a path blockage signal for any light path intersecting said first one of said light paths.

Claim 11

A touch panel as set forth in claim 7, said component failure detection means including means for testing the operability of a selected one of said elements by performing the steps of: enabling said selected element and a complementary element across said display surface from said selected element, and testing for the presence of a blocking signal; enabling the same complementary element and a second element of the same type as said selected element and which is located near said selected element, and testing for the presence of a blocking signal; and denoting the detection of a component failure if a blocking signal is detected when said selected element is enabled, but no blocking signal is detected when said second element is enabled.

Claim 12

A touch panel as set forth in claim 8, wherein said component failure detection means includes means for displaying a message on said display surface requesting the user to prevent any objects from touching said display surface.

Claim 15

A method as set forth in claim 10, said comparing step including the step of comparing said path blockage signals from a plurality of scans of said display surface with predefined size and time duration criteria.

Claim 16

A method as set forth in claim 10, said comparing step including the step of comparing said path blockage signals from a plurality of scans of said display surface with one or more criteria selected from the set consisting of: a minimum size criteria, a maximum criteria, and a minimum tim duration criteria.

Claim 17

A method as set forth in claim 10, further including the step of testing the operability of a selected one of said elements by performing the steps of: enabling said selected element and a complementary element across said display surface from said selected element, and testing for the presence of a blocking signal; enabling the same complementary element and a second element of the same type as said selected element and which is located near said selected element, and testing for the presence of a blocking signal; and denoting the detection of a component failure if a blocking signal is detected when said selected element is enabled, but no blocking signal is detected when said second element is enabled.

Claim 18

A method as set forth in claim 12, further including the step of sequentially testing the operability of all of said elements.